Is it permissible to stop a vehicle directly behind a visible indicator post?

In the photo, in winter, you are approaching a level crossing; on the right there is sign A-10 "level crossing without barriers", and below it a white and red countdown marker post with three bars - G-1a. Parking directly beyond this post is allowed. The answer is: yes.

The Road Traffic Act prohibits parking before and after a level crossing, on both sides of the road, on the stretch from the level crossing to the countdown marker post with one bar. The Regulation on road signs and signals explains that the post with three bars is placed below the warning sign, the post with two bars at 2/3 of the distance between the crossing and the sign, and the post with one bar at 1/3 of this distance, closest to the tracks. So the parking ban starts only from the post with one bar, the one closest to the tracks; beyond the post with three bars, which stands furthest from the crossing, parking is not prohibited by this rule. Of course, the general rules apply: the vehicle must be visible from a sufficient distance, must not obstruct traffic or hide a sign, and outside a built-up area it should stand off the roadway, if possible.

Legal basis: Art. 49 para. 2 point 3 and Art. 46 para. 1 and 3 of the Road Traffic Act (Prawo o ruchu drogowym); § 78 para. 1 and 2 and § 6 para. 2 of the Regulation on road signs and signals